In-situ scanning probe microscopy of solid-liquid interfaces: role of epitaxial oxide adlayers on Cu electrodeposition

We discuss how the nanoscale structural and chemical properties of copper (Cu) single crystal surfaces immersed in acidic aqueous solutions affect local electrochemical function. In particular, perturbation of oxide adlayers with in-situ atomic force microscopy (AFM) is shown to locally enhance the electrochemical deposition of Cu on Cu electrode surfaces. The results are consistent with a heterogeneous nucleation and growth mechanism in which the tip-sample interaction creates surface defect sites in passivating oxide adlayers which are active towards the electrochemical adsorption of Cu species. This 'protect-deprotect-react' scheme enables precise control of feature sizes and allows this technique to be used for fabrication and constructive modification of solid-liquid interfaces.